Hi!
Support matrix shows that 7.5 SP1 supports SQL 2012 SP1 (ITMS Platform Support Matrix |Sep 2014|)
http://www.symantec.com/business/support/index?page=content&id=HOWTO9965
Looks like for now you have to use only SQL Server 2012 SP1 for 7.5 SP1 (HFx) release.
If support matrix doesn't contain information that 7.5 SP1 release supports SQL 2012 SP2, then it means that SP2 wasn't certified and isn't officially supported for now, within 7.5 SP1 release.
Thanks,
IP.